hybrid pagination

pkg/response/response.go

@@ -1,11 +1,13 @@
 package response
 
 import (
+	"errors"
 	"net/http"
-	"strconv"
 
 	"github.com/asaskevich/govalidator"
 	"github.com/labstack/echo/v4"
+
+	orm "tm/pkg/mongo"
 )
 
 // APIResponse represents a standard API response structure
@@ -26,17 +28,17 @@ type APIError struct {
 
 // Meta represents metadata for paginated responses
 type Meta struct {
-	Total      int    `json:"total,omitempty"`
+	Total      int    `json:"total"`
 	Limit      int    `json:"limit"`
 	Offset     int    `json:"offset"`
-	Page       int    `json:"page,omitempty"`
-	Pages      int    `json:"pages,omitempty"`
+	Page       int    `json:"page"`
+	Pages      int    `json:"pages"`
+	HasMore    bool   `json:"has_more"`
 	NextCursor string `json:"next_cursor,omitempty"`
-	HasMore    bool   `json:"has_more,omitempty"`
 }
 
 type Pagination struct {
-	Limit     int    `query:"limit" valid:"optional,range(1|100)" default:"20"`
+	Limit     int    `query:"limit" valid:"optional,range(1|100)" default:"10"`
 	Offset    int    `query:"offset" valid:"optional,range(0|1000000)" default:"0"`
 	Cursor    string `query:"cursor" valid:"optional"`
 	SortBy    string `query:"sort_by" valid:"optional"`
@@ -192,59 +194,16 @@ func Parse[T any](c echo.Context) (*T, error) {
 	return &form, nil
 }
 
-func NewPagination(c echo.Context) *Pagination {
-	limit, err := strconv.Atoi(c.QueryParam("limit"))
-	if err != nil {
-		limit = 20
-	}
-
-	offset, err := strconv.Atoi(c.QueryParam("offset"))
-	if err != nil {
-		offset = 0
-	}
-
-	sortBy := c.QueryParam("sort_by")
-	if sortBy == "" {
-		sortBy = "created_at"
-	}
-
-	sortOrder := c.QueryParam("sort_order")
-	if sortOrder == "" {
-		sortOrder = "desc"
-	}
-
-	cursor := c.QueryParam("cursor")
-
-	return &Pagination{
-		Limit:     limit,
-		Offset:    offset,
-		Cursor:    cursor,
-		SortBy:    sortBy,
-		SortOrder: sortOrder,
+// PaginationBadRequest writes a 400 response for invalid list pagination parameters.
+func PaginationBadRequest(c echo.Context, err error) error {
+	msg := "Invalid pagination parameters"
+	if errors.Is(err, orm.ErrInvalidCursor) {
+		msg = "Invalid pagination cursor"
 	}
+	return BadRequest(c, msg, err.Error())
 }
 
-// Response calculates offset-based pagination metadata.
-func (p *Pagination) Response(total int64) *Meta {
-	return p.ListMeta(total, "", false)
-}
-
-// ListMeta builds pagination metadata for list endpoints (offset and/or cursor).
-// When total is negative, total/page/pages are omitted (count was skipped).
-func (p *Pagination) ListMeta(total int64, nextCursor string, hasMore bool) *Meta {
-	meta := &Meta{
-		Limit:      p.Limit,
-		Offset:     p.Offset,
-		NextCursor: nextCursor,
-		HasMore:    hasMore,
-	}
-	if total >= 0 {
-		pages := (total + int64(p.Limit) - 1) / int64(p.Limit)
-		meta.Total = int(total)
-		if p.Limit > 0 {
-			meta.Page = p.Offset/p.Limit + 1
-		}
-		meta.Pages = int(pages)
-	}
-	return meta
+// IsListPaginationError reports client-facing pagination errors from list queries.
+func IsListPaginationError(err error) bool {
+	return IsPaginationError(err) || errors.Is(err, orm.ErrInvalidCursor) || errors.Is(err, orm.ErrInvalidPagination)
 }